Self-Aligned Double Patterning (SADP) can be adopted to form small pitch patterns, e.g., memory cells with a small pitch. The SADP technique may form repeating small-pitch patterns and spaces on a semiconductor substrate. However, if large-pitch patterns also need to be formed on other areas of the semiconductor substrate, the small-pitch patterns and the large-pitch patterns may need to be formed separately, which causes complicated fabrication processes.